Double-Layer Circuit Structure with High Heat-Dissipation Efficiency

Abstract

The present invention relates to a double-layer circuit structure with high heat-dissipation efficiency, comprising: a first thermal-conductive and electric-insulating layer, a plurality of first metal pads, a second thermal-conductive and electric-insulating layer, a circuit layer, and an anti-soldering layer. In the double-layer circuit structure, the second thermal-conductive and electric-insulating layer disposed on the first thermal-conductive and electric-insulating layer has a plurality of openings, and a plurality of second metal pads of the circuit layer on the second thermal-conductive and electric-insulating layer are connected with the openings, respectively. Thus, after each of devices to be welded are soldered on two second metal pads, the solder would flow into the openings through the soldering points between the devices to be welded and the second metal pads, so as to sequentially flow onto the first metal pads. Therefore, the flow path of the solder becomes a heat-dissipating shortcut for heat dissipation.

What is claimed is: 
     
         1 . A double-layer circuit structure with high heat-dissipation efficiency, comprising:
 a first thermal-conductive and electric-insulating layer;   a plurality of first metal pads, being disposed on the first thermal-conductive and electric-insulating layer;   a second thermal-conductive and electric-insulating layer, being disposed on the first thermal-conductive and electric-insulating layer, and having a plurality of openings, wherein each of the openings are located over the inner edges of each of the first metal pads, respectively;   a circuit layer, being formed on the second thermal-conductive and electric-insulating layer, and having a main circuit and a plurality of second metal pads connected to the main circuit, wherein each of the second metal pads are connected with the outer edges of each of the openings, respectively; moreover, each of the second metal pads and the openings are respectively located over each of the first metal pads when the second thermal-conductive and electric-insulating layer covered the first thermal-conductive and electric-insulating layer; and   an anti-soldering layer, covering the circuit layer, and having a plurality of soldering windows for exposing the second metal pads out;   wherein a plurality of devices to be welded are respectively soldered on the second metal pads via the soldering windows after being disposed on the anti-soldering layer, such that the devices to be welded are electrically connected to the circuit layer; moreover, each of the devices to be welded being soldered on two second metal pads, and the solder would flow into the openings through the soldering points between the devices to be welded and the second metal pads, so as to sequentially flow onto the first metal pads; therefore, the flow path of the solder becomes a heat-dissipating shortcut for heat dissipation.   
     
     
         2 . The double-layer circuit structure with high heat-dissipation efficiency of  claim 1 , wherein the main circuit consists of a positive line and a negative line. 
     
     
         3 . The double-layer circuit structure with high heat-dissipation efficiency of  claim 1 , wherein the first thermal-conductive and electric-insulating layer is further formed with at least one connecting line thereon, used for connecting the first metal pads. 
     
     
         4 . The double-layer circuit structure with high heat-dissipation efficiency of  claim 1 , wherein the device to be welded is an LED device. 
     
     
         5 . The double-layer circuit structure with high heat-dissipation efficiency of  claim 1 , wherein the shape of the first thermal-conductive and electric-insulating layer and the second thermal-conductive and electric-insulating layer is selected from the group consisting of:
 rectangle, circle and combination of above two shapes.   
     
     
         6 . The double-layer circuit structure with high heat-dissipation efficiency of  claim 3 , the anti-soldering layer is a white paint sprayed on the circuit layer. 
     
     
         7 . The double-layer circuit structure with high heat-dissipation efficiency of  claim 3 , the anti-soldering layer is a white reflective sheet disposed on the circuit layer.